Co-Cu alloy nanoparticles decorated TiO_2 nanotube arrays for highly sensitive and selective nonenzymatic sensing of glucose

摘要

A nonenzymatic glucose sensor was fabricated by electrodepositing cobalt rich cobalt-copper alloy nanoparticles (Co-CuNPs) on vertically aligned TiO_2 nanotube (TDNT) arrays. For this, TDNT arrays with tube diameter of 60 nm were synthesized by electrochemical anodization. The composition of the elec-trodeposited alloy was optimized based on the electrocatalytic activity towards glucose oxidation. This is achieved by controlling the concentration of electrolyte and time of deposition. Chemical composition of the optimized Co-Cu alloy nanoparticles is determined to be Cu_(0.15)Co_(2.84)O_4 with fcc crystalline structure. The sensor showed two linear range of detection with high sensitivity of 4651.0 μAmM~(-1) cm~(-2) up to 5 mM and 2581.70 μAmM~(-1) cm~(-2) from 5 mM to 12 mM with a lower detection limit of 0.6 μM (S/N = 3). The sensor is highly selective to glucose in the presence of various exogeneous and endogeneous interfering species and other sugars. The response of the sensor towards blood serum was in good agreement with that of commercially available glucose sensors.